VMD is an interactive molecular visualization and analysis pro- gram currently under development at the Resource.It is the primary visualization tool used by researchers at the facility and has been used by many other groups for a wide variety of tasks including docking studies, structure refinement, trajectory analysis, semiconductor physics, and the production of chemistry edu- cation videos. When used as part of MDScope, VMD is the visual front-end tothe molecular dynamics program NAMD, also under developmentat the Resource. VMD enables researchers to view biomoleculesusing a wide variety of rendering and coloring methods, as well asto analyze a structure and display the results. When a trajectoryis available, either from a data file or via a connection to a runningNAMD simulation, the molecules can be animated to visualize themotions. VMD is being used to experiment with new types of input and display mechanisms, and it supports a wide range of devices including a large-screen stereo projection system, the CAVE,and spatial tracking devices. This program, with complete C++source code, documentation, and precompiled binaries for SGIs, is freely available to the molecular modelling community via anonymous ftp. Additional information on VMD may be found on the VMD web page at http://www.ks.uiuc.edu/Research/VMD.